Climbing skins are used to assist a person on skis or another form of snow travel aid to ascend a slope. At one time, climbing skins were made from the skins of fur bearing animals. Modern climbing skins are manufactured and comprise material with a nap of fibres that project at similar angles. A strip of such material is attached to the base (undersurface) of a snow travel aid so that the fibres project outward and are angled rearwardly. This limits rearward slippage on snow while allowing relatively unimpeded forward sliding. Through the use of climbing skins, a user can ascend a relatively steep snow slope by sliding forward on one skin, and then the other.
Some snow travel aids are manufactured to include a permanent climbing skin attached to and usually embedded in, the base of the aid. In most situations, use of a removable climbing skin is preferred. Removable climbing skins are usually attached to the base of a snow travel aid by means of mechanical fasteners (such as straps or clips), glue or both. Glue for removable climbing skins is adapted to remain sticky at low temperatures and permit repeated removal and attachment of the skin from the base of the snow travel aid.
Material for removable climbing skins is available in a variety of widths. Typically, a user will acquire a sufficient length of the material to cover the bottom of the snow travel aid from approximately end to end. The user may select a pre-cut strip of material having a width less than the narrowest portion of the aid's base (i.e., the “waist” of a ski). Due to the shape of the bottom surface of many modern sliding snow travel aids, fitting a climbing skin in this manner will leave forward and rearward portions of the base not covered by the material. Exposed areas of the base reduce the amount of grip that may be possible between the aid and snow and also provides areas which if weighted, may result in rearward slippage on the snow. To compensate, a user may trim the lateral edges of a strip of climbing skin material to match each side contour of the base of the snow travel aid thereby permitting the material to cover more of the base. However, if a climbing skin is trimmed so that the skin material extends right to each bottom side edge on the base, the user may then encounter difficulties in “setting” an edge when needed on icy surfaces because the bottom surfaces of the edges are covered. This is particularly a problem with the hard bottom side edges (e.g., metal edges) typically provided on the base of a sliding snow travel aid which are intended to bite into ice and hard snow. To compensate for the latter disadvantage, a user may trim the lateral edges to provide a small offset from the side of the snow travel aid thereby exposing a portion of the base of the aid adjacent the edge.
Trimming climbing skins apart from a snow travel aid to provide an offset can be done by measurement or approximation and can also be done using the aid as a pattern. The latter procedure is accomplished by positioning a strip of climbing skin material against the base and covering both side edges of the aid. The user then trims a first side using a blade held against one edge of the aid as a guide. This results in the first side being trimmed to exactly match the contour of one side edge of the aid. The climbing skin is then repositioned on the base by moving the material a certain distance laterally away from the trimmed side, followed by trimming of the second side in the same manner as the first. The lateral distance is chosen to be double the desired offset between one side edge of the aid and the corresponding climbing skin edge. The skin is then repositioned centrally on the base so that each edge of the climbing skin is offset inwards from the corresponding base side edge the desired amount so as to reveal both side edges on both sides of the aid. For example, when the aid comprises the metal bottom side edges typical of a modern downhill or touring ski or a snowboard, the offset is usually selected so as to reveal at least the entirety of the underside of each metal edge.